1. Technical Field
The present invention relates to a zoom lens, and more particularly to, a zoom lens having a diffraction plane, a camera having the zoom lens, and a portable information device having the zoom lens.
2. Description of the Related Art
Market of cameras used for security and the like are widened, and demands are also increased in various fields. Among the demands, high image quality and high magnification changeability are desired by users, and weight thereof is large. Therefore, even in the zoom lens used as a photographing lens, the reconciliation of high performance with high magnification changeability is often required.
In terms of high performance, a configuration having a resolving power corresponding to imaging elements of at least 1 mega to 5 mega pixels over the entire zoom range is desired. In addition, it is considered that a magnification changing ratio of about X16 is preferred as the high magnification changeability.
It is also preferable that aberrations be sufficiently corrected even in a near infrared wavelength range so that photographing is available even in a dark state.
In addition, widening of an angle of view is also preferred, and preferably, a half angle of view at a short focal end of a zoom lens is 25 degrees or more.
In addition, large-diameter of a lens is also preferred, and preferably, an F number at a short focal end (sometimes, referred to as “wide angle”) is 2.0 or less.